It is our belief that soft wash chemicals, in their diluted form and as used on a customer's property, should be legal and safe for people, materials and our environment.
Benz Blackwash at 5:1-10:1 dilution is not classed by the EU, PCD or HSE as corrosive or hazardous to people or our environment.
We designed this powerful biocide product specifically for tough stain removal from rendered walls, footpaths, concrete patios & drives, roofs, sandstone, limestone and most other exterior surfaces.
The active ingredient is sodium hypochlorite, a powerful oxidiser that removes the most troublesome of black, red and green stains from exterior hard surfaces.
This powerful surfactant "sticks" the active ingredient to the surface – ensuring a higher contact time – which means the low, and therefore safe, concentrations of chlorine in Blackwash can work with extremely high effectiveness.
This means Blackwash is safer for the operator, for the general public, and for our environment than formulations that contain high concentrations of chlorine.
It is approved by:
• The Irish PCD (Pesticide Control Division)
• The UK HSE (Health & Safety Executive)
We supply Blackwash as a specialised ready-mixed soft wash biocide that does not bio-accumulate.
It produces exceptionally rapid results on porous surfaces – such as render – and produces a near instant cleaning effect on smooth, non-porous surfaces such as cladding and UPVC.
It can be used as a stand-alone soft wash solution or in conjunction with power washing or Benz Biocidal Wash.
Click the links below to go direct to the section you are interested in:
All surfactants are not created equal. The properties can vary dramatically and it is not a matter of "just adding Fairy Liquid to hypochlorite".
BENZ Blackwash uses a special type of highest quality surfactant to:
1) Maintain a stable solution that can be stored for longer than would be the case with cheap, less effective surfactants.
2) Formulate a solution that is a highly effective "wetting agent" that rapidly soaks into the "biofilm" (the layer of biological growth that gives rise to the dirty stains that customers want removed) and thus increases the effectiveness and speed of operation of the active ingredient.
3) Ensure that the the surfactant does not break down the sodium hypchlorite – which many inferior surfactants will do – and thus minimise the production of chlorine ( a big problem if strong sodium hypochlorite is used with a cheap and inferior surfactant).
4) Create a product that adheres (or "sticks") effectively to the surface being cleaned, ensuring the active ingredient stays in contact with the biological growths for the longest possible time (which enables Blackwash to be highly effective using a safer % of chlorine than would otherwise be the case).
5) Reduce run-off from walls and roofs into drains and the environment.
6) Ensure the surfactant complies with all EU biodegradability requirements for surfactants.
Because of the high quality surfactant, 5 litres of Blackwash will do much more work, more effectively, covering a larger area, than will 5 litres of ordinary commercial sodium hypochlorite – and it will do it far more safely.
Unlike commercial sodium hypochlorite that has a 15% concentration of chlorine, and which therefore has intrinsic dangers to the operator and customer, BENZ Blackwash as delivered in concentrated form contains 10% chlorine.
This lower % of chlorine means the product is both safer and will last longer that raw industrial sodium hypochlorite. This is because the higher the % chlorine content, the faster the product will degrade.
And as applied to actual surfaces Benz Blackwash contains only 0.5-2% chlorine – making it safe for the operator, customer, the customer's property, and the general public.
High strength sodium hypochlorite poses an high health risk. Most Health & Safety reps in large companies will not allow their employees spray corrosive liquids, which is why we created BENZ Blackwash to be safe for all concerned.
We use special vented caps. Blackwash containers come with special vented caps which allow for the gradual and completely safe release of a small amount of vapour that the product naturally produces. If Blackwash is decanted into another container always ensure vented caps are used.
Quality control: To ensure the highest possible production quality we have Blackwash manufactured for us by one of Ireland's leading chemical companies who hold the ISO 9001:2000 accreditation in quality control.
Yes. We recommend using Blackwash at 10:1 on UPVC as at higher concentrations the UPVC may turn salmon pink if not rinsed off after 10 minutes. This is nothing to be concerned about, and the surface will return to its natural white in a few hours, but customers are happier if this does not happen.
Blackwash is a highly effective way to clean ingrained black staining from UPVC guttering, fascia, soffits, windows, doors, and frames. It brings them up wonderfully clean, ready for rinsing with a standard Water Fed Pole (WFP) window cleaning system.
How to apply Blackwash to UPVC: Simply spray using a Benz 10 Soft Wash Spray Nozzle and rinse off after about 15-30 minutes. We use a power washer with a rinsing nozzle that shoots a low pressure jet (you can put your hand in front of it) that mostly eliminates the need for brushing or scrubbing. The water force is usually enough to shift the dirt without damaging the surface.
If you don't have power washer you can use a water fed pole with a brush to rinse off Blackwash. We've found this especially effective for smaller jobs, when it's not worth the time needed to set up a power washer.
Btw: Benz Blackwash is excellent for giving windows a special gleam and sparkle that customers love.
Yes, completely safe. Watch this video for a quick explanation.
Does Blackwash damage render by leaving hydrochloric acid in the substrate?
No. Not at all.
KRend – one of the largest suppliers of wall render – in their own words (from a pdf they supply on recommended methods of cleaning efflorescence from their render) state:
"Generally, an 8% solution of commercial grade hydrochloric acid is used. The acid concentration can be adjusted to suit individual circumstances; a less concentrated solution will require more applications to remove lime bloom but will be less likely to result in an acid etched appearance."
We think it reasonable to any clear-thinking person that if KRend advocate the use of hydrochloric acid to clean their products, the extremely small amount that may be produced by the application of Benz Blackwash is certainly acceptable.
However, we wanted to be 100% sure that Blackwash is safe to clean KRend, and by extrapolation, all other renders, so we asked the chemist in charge of developing Blackwash what the reality was. This is his response:
"Given the dilution you are using (5:1–10:1) it would not be possible to produce 8% hydrochloric acid. The amount, if any, produced would be minimal as hypochlorite is alkaline. Also I assume your usage instructions include a thorough rinsing after use (they do) which will wash away all by-products or residues from the cleaning process."
We think these combined statements should be enough for any clear-minded and reasonable person to feel safe and confident in using Blackwash to clean KRend and other renders.
Because concentrations of over 2% available chlorine (Benz Blackwash diluted 5:1) are corrosive to building materials, windows, rubber seals, gutter seals, and so on. It can also damage equipment such as pumps and poses a severe health and safety risk to people and our environment (scroll down for detailed Health and Safety and environmental information).
Therefore we created Benz Blackwash to be as safe as possible for people and property. You'll find that your customers will appreciate the fact that you are using a product that is government approved for the professional cleaning of exterior hard surfaces.
Sometimes applying two, or occasionally three, treatments – rinsing between applications – is a small price to pay for maintaining the safety of a customer's property, ensuring the customer stays safe, and ensuring the operator stays safe. And of course it's a small price to pay for protecting our environment, which we all depend upon for our survival and well-being.
Industrial sodium hypochlorite is vastly less effective per unit quantity – and much less kind to our environment, humans, and our customer's property – than is Benz Blackwash.
At first glance we know it may appear that similar results to Benz Blackwash could be achieved using cheap industrial grade sodium hypochlorite. But ordinary 15% chlorine sodium hypochlorate has a number of serious drawbacks and real dangers.
Note: All sodium hypochlorite is not created equal. The quality (strength and purity) of the cheaper products can vary. As is usually the case, we get the quality we pay for.
Btw: Did you know that the higher the strength of sodium hypochlorite the faster it degrades when stored? So because Benz Blackwash is formulated using a relatively low concentration of sodium hypochlorite, it can be stored for longer than 15% chlorine sodium hypochlorite.
Dangers arise from the high level of "run off" from the surface being cleaned when using industrial sodium hypochlorite:
The dangers of using high chlorine industrial sodium hypochlorite:
It is highly unlikely that commercial sodium hypochlorite will have an SDS sheet
You will have no support when using high chlorine sodium hypochlorite
Btw – Your Insurance Cover: Because of the high risk to the operator, customers, customer's property, and our environment (the legal consequences of infringing government legislation are increasingly serious) from using high strength industrial sodium hypochlorite, we suggest talking to your insurance company about the possible consequences before using it.
Back to Top
The hidden costs of using industrial sodium hypochlorite:
Benz Blackwash prices on the other hand include ready-mixed fragrance and the highest quality surfactant – and include FREE SHIPPING.
We believe that, in real terms, the small extra investment in BENZ Blackwash is more than justified given the:
Sodium hypochlorite – at the level of concentration as used in Benz Blackwash – is recommended by the leading render manufacturers KRend and Weber as being suitable for cleaning the surfaces of buildings coated with their products. Also by Kingspan, the leading manufacturer of industrial steel cladding.
Ordinary industrial sodium hypochlorite with high levels of chlorine will leave behind excessive salts that could potentially damage the surface being cleaned, causing deterioration.
But Benz Blackwash has been formulated so the minimum amount of chlorine is needed for stain removal – less than 2% on the heaviest of soiling – thus salts are kept to minimum.
The breakdown of chlorine into common salt is the reason we thoroughly rinse surfaces after stain removal with plenty of fresh water.
Watch this short (only 1:38) video see the stunningly fast and dramatic way BENZ Blackwash cleans this timber cladding: (Note: This effect was achieved using Blackwash at the standard 10:1 dilution, which means only 1% chlorine is being applied, with no unpleasant odour)
Btw: Tarmac: In general we do not advise using Blackwash to clean tarmac. Wet down any tarmac that may be exposed to run-off from the surfaces being cleaned before applying Benz Blackwash.
We suggest treating tarmac with Benz Biocidal Wash at 50:1 (25:1 or two coats at 50:1 for heavy infestation), which will usually show excellent results within 24 hours.
Common everyday uses of sodium hypochlorite: Babies bottle sterilising fluids contain 2% sodium hypochlorite. We bathe our children in swimming pools for hours at a time at up to 0.25% sodium hypocholrite and drink chlorinated water with up to 0.005% sodium hypoclorite. And dentists use it during deep surgery.
Benz Blackwash contains sodium hypochlorite as an oxidiser. It is this oxidising process that makes Blackwash such a highly effective cleaning solution. Sodium hypochlorite's strength in a product and during application are normally referred to by a percentage of chlorine.
There has been much confusion about the reality of the effect of sodium hypochlorite, when used responsibly and in accordance with Health and Safety guidelines, on both humans and the environment.
This is because most easily available data refers to sodium hypochlorite above 10% strength.
And its properties differ dramatically when used in a 25% concentration for industrial bleach to 0.005% concentration in our drinking water.
At 25% it is harmful to the environment, can cause extremely nasty burns to skin and is highly corrosive. At 15%, the strength most commonly available, it will also cause skin irritations and is classed as corrosive. At 10%, the strength of concentrated Benz Blackwash, it is much less irritating and only slightly corrosive.
A note about drains: It is important to protect our environment by minimising run-off into sewers and surface drains. Run-off can be kept to minimum or zero by using BENZ Nozzles along with skillful spray and brush control techniques. If some run-off to drains is unavoidable, block the drains and/or gutter downpipes until application has been concluded.
Low environmental impact: At 0.5-2% concentration, sodium hypochlorite is unclassified. Therefore using BENZ Blackwash at a 5:1-10:1 mix, the heavily diluted rinse residues from hard surface cleaning can be washed into foul drains – where the very small amount of remaining chemical rapidly breaks down upon contact with organic matter.
Smell & Fragrance: In its pure form there is a slight smell that some people find unpleasant. So we add a fragrance to Blackwash to make the process of stain removal more pleasant for both end customers and operatives.
Btw: Our comparision tests with other commercially available surfactant/fragrance combinations, which are added to industrial grade 15% chlorine sodium hypochlorite, showed that they do not adequately mask the odour of chlorine.
This means that in use there is a highly unpleasant "bleach" smell.
We've also noticed during our tests that the quality of surfactant often is simply not up to the job.
In contrast we estimate that Blackwash is about 10 times more pleasant to use. Indeed, some people have commented that the aroma that can be detected when treating large areas can actually be quite agreeable.
Available Chlorine: Commercial sodium hypochlorite has 10-15% available chlorine. Domestic bleach has 5%. And Benz Blackwash in use has only 0.5-2%, which makes it safe for humans and for our environment.
Non-carcinogenic: Sodium hypochlorite at the levels used in Benz Blackwash is "not classifiable" as to its carcinogenic effect on humans.
Blackwash is best applied using a low-pressure spray system. Then simply rinse off using a garden hose or, on suitable surfaces, a power washer using low pressure and/or a fan jet.
Btw: Blackwash has an alkaline pH and surfactant, which, along with the agitation of spraying and gentle brushing, loosens the biological growth and helps facilitate its removal during rinsing
A maintenance spray with Benz Biocidal Wash every 1-3 years should be enough to keep most surfaces permantly clean.
Test before applying: Always test a cleaning chemical on a small, obscure area of the surface to be cleaned if you are not familiar with the effect of the chemical on that particular surface.
Applying to metals: The same advice to test before applying a cleaning chemical applies to metals. We recommend wetting metal surfaces before applying a cleaning chemical to prevent streaking.
Typically 30-40L will be used by a one-man contractor per day to treat all the elevations of a large detached house, including the paths and drive. Some jobs may require as little as 5L, while large contractors can use up to 100L per day.
As a rough guide, 5L of Blackwash will create 30L of mix, which will treat 40-50 square metres of a porous surface at 5:1 and double that at 10:1.
The coverage of Blackwash is dependant on many factors, such as:
Again as a rough guide, 10L Blackwash will make 60 litres of mix at 5:1, which will be enough to clean a very dirty (needing two applications) large gable end of a rendered house. It would also be sufficient to clean an average two-car Cobblelock driveway.
10L Blackwash will make 110L mix at 10:1. On smooth, non-porous surfaces such as cladding or painted surfaces this quantity will clean approximately 300 square metres, which is about three times the amount of cladding cleaned in the cladding cleaning guide photos on this website.
Back to Top
Always thoroughly rinse Blackwash from the surface being treated after allowing 30-60 minutes for the cleaning action to take effect.
This ensures the salts left behind by the breakdown of chlorine, which could potentially damage the surface if left, are removed.
Also, we advise rinsing between applications of Blackwash. On many jobs only one application is sufficient. But if the staining is bad, two treatments – and exceptionally three – may be required.
Rinsing off the previous coating of Blackwash removes the "debris" from the pores of the surface, thus allowing subsequent applications to penetrate more deeply and clean more effectively.
If you are going to apply Benz Biocidal Wash following a Blackwash treatment it is important to give an especially thorough rinsing. This is to remove any surfactant that may be left behind, which could impede the Biocidal Wash being fully effective.
On porous surfaces we recommend spraying the first treatment, then gently brushing each subsequent application of Blackwash into the surface. This allows the product to penetrate the biological growth to the maximum depth, increasing its effectiveness.
Keeping Blackwash cool will greatly extend its shelf-life
When working with chemicals always keep your equipment and personal protection equipment (PPE) clean. Take care to protect yourself from accidental contact with your eyes and skin. Wear chemical resistant protective gloves, and chemical resistant clothing that covers your whole skin surface, and a full face visor that includes protection for your hair. Wash all PPE with fresh water before taking breaks, before eating, drinking and smoking, and at the end of each working day.
Always treat a small, obscure test patch on a customer's property before using any chemical cleaning product and obtain your customer's agreement that the effect of the applied chemical is acceptable before cleaning the entire property.
The purchaser and/or end users are solely responsible for ensuring that these products are used in line with industry Approved Codes of Practice. All operators must be competent in using and applying any Ministry Approved professional product. Always read the label and product information before use. By proceeding you are purchasing a professional biocide product. You must ensure the end user of these products complies with the PCD/HSE Code for the safe professional use of biocides and is competent in using biocides safely.
During use and application always adhere to the SDS and follow the product labelling instructions and the product information supplied on this website to ensure protection of our environment and avoidance of injury to humans and animals.
Data Sources: Further technical information regarding the use of biocides can be obtained from the European Chemicals Agency, the UK health and Safety Executive (HSE), and the Irish Pesticides Control Division (PCD).
* As far as we know at the time of writing there is no other sodium hypochlorite based biocide available in the UK or Ireland that is fully approved by the HSE, PCD, and is REACH compliant for soft washing exterior hard surfaces.